On Faunistic Coloration

Page 1

ON FAUNISTIC

ON FAUNISTIC

273

COLORATION.

COLORATION.

BY ERNEST A . ELLIOTT, F . Z . S . , F . E . S . ,

etc.

COLOUR depends upon s t r u c t u r e ; hence, where there is no structure, colour is lacking, T h e universally accepted division of the Animal World is into (1) Invertebrata, without backbone, and (2) Vertebrata, with backbone ; b u t from the present point of view it may be divided into (1) Protozoa, with no especial organs, and (2) Organozoa, possessing organs. T h e Protozoa are a sub-kingdom of the Invertebrata, the simplest of which consist of a structureless and colourless mass of protoplasm ; some possess a cell-like pulsating body, called the contractile vesicle, the function of which is not known, and in it we find the first trace of colour, a faint pink. T h e Radiolaria present the first differentiation of parts, a central mass of cells with an external coating; here we find pronounced colours. In Sporiges certain cilia-lined cells suck in water, containing food, and eject the exhausted fluid ; these cells are the first t r u e organs f o u n d in the animal kingdom and are often vividly pigmented. M a n y seaside visitors t o Bawdsey Cliff are familiar with the horny brown tubes attached to shells and stones, Tubiilaria. Their inhabitants show at the orifice a double set of tentacles, which are coloured f r o m pale pink to vivid red. T h e true Jellyfish, Medusa, often display bright hues, arranged along the canals and on the rudimentary eye-spots. U p to this point all the creatures are transparent, with internal tints. Turning now to the Actinozoa (sea Anemones and Corals), we find the body more opaque and the colour applied externally. In the Anemones the colour greatly varies in the same species but the pattern remains constant. T h e column or body is often brightly pigmented or spotted, and the tentacles always of a sharply contrasting hue ; moreover the eye spots, and a zone round t h e body, are almost always azure. Corals are like colonies of single Anemones, b u t with a stony skeleton ; the tentacles protruding tro.m the orifices are always brilliantly coloured, making the w m g coral-reef like a luxurious tropical flower-garden. In t h e ' Jrganpipe Coral (Tubipora musica, Linn.) the t u b e is deep red or crimson, the polyp vividly emerald green ; and, in the Red Coral ot commerce (Corallium nobile, Linn.) the polyp is white. e find then, no colour in structureless P r o t o z o a ; the r u d i mentary organ, where present, slightly decorated. I n transparent


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.
On Faunistic Coloration by Suffolk Naturalists' Society - Issuu